Sewing machine attachment for circular feed



Sept 13, 1955 H. F. szczEPANsKl ET AL 2,717,565

SEWING MACHINE ATTACHMENT FOR CIRCULAR FEED Filed July l, 1954 s, ZM m/y Nwm, wmm mdk@ www He, m@

United States Patent' O SEWING MACHINE ATTACHMENT FOR CIRCULAR FEED Henry F. Szczepanski and William R. Albright, Lander, Wyo'.

Application July 1, 1954, Serial No. 440,662

8 Claims. (Cl. 112-214) This invention relates to an attachmentfor. use in guiding work during sewing. operations in a standard. sewing machine and it relates more particularly to a sewing, machine attachment for guiding the textile material and other work .for swinging movement to effect sewingin a circular or other uniform curvilinear pattern in the material.

To the best of our knowledge, none of the standard sewingV machines which have heretofore been produced embody means other than to advance the material linearly for effecting sewing operations in a straight line in the work during normal operations of the machine. The material may be guided by hand for movement other than linearly through the machine but it is diiiicultto rely upon manual control for guiding the work to produce stitching in a uniformly curvilinear pattern and the like.

It is an object of this invention to produce a simple and inexpensive attachment which may be easily secured in position of use with a. standard sewing machine for operation to guide the work. inswinging movement during normal operation of the machine to elfectsewing operationsin a curvilinear or in a circular or other curvilinear pattern of uniform dimension, which enables adjustments to be made for varying the diameterof. the circular pattern and in which such adjustments may be made in a simple and eiiicient manner, and. which maintains a uniform gripping relation with the material necessary for control thereof for guiding the material in swinging movement during displacement in normal operations of the machine.

It is another object of this invention to produce an attachment which' is adapted removably to be secured ing the work as it is being advanced by the machine to in position of use in standardr sewing machines for guidproduce stitches in a circle pattern of xed andvariable dimensions and with possible adjustments for the production of other curvilinear designs in the work such as spirals, ovals and the like.

These and other objects and advantages ofthis invention will hereinafter appear and for purposes of'illustration, but not of limitation, an embodiment of the invention is shown in the accompanying drawing in which- Figure 1 is a perspective elevational view of the attachment embodying features of this invention in position of use in the machine, and

Figure 2 is a sectional elevational view in perspective taken substantially along the line 2-2 of Figure 1.

Description of the sewing machine attachment embodying features of this invention will be made in connection with a standard machine having aframe 10, a needle holder 11 reciprocable vertically in said frame with a sewing needle 12 secured to depend from the-end thereof, a presser plate 13, a bed plate 14, a work advancing foot or feed dog member 15 movable reciprocally in the bed plate, and a slide door 16 for concealing a bobbin mechanism located to one side and beneath theV bed plate.

Bn'eily described, the attachment makes use of a rotat- Patented Sept. 13, 1955 ICC able member in the form of a turnable T mounted for free rotational movement ina journal and which is offset from alignment from the sewing needle 12 of the sewing machine. The work is adapted to be xed on the turntable with its center or axis as the pivot so that the feeding instrumentalities of the machine, during normal operation of the machine, will cause the work to swing with the turntable as its pivot to produce stitches in a pattern forming a true circle having a radius corresponding to the distance between the sewing needle and the axis of the turntable. The turntable is adapted to be mounted for adjustments to increase or decrease the spaced relation with the sewing needle for producing curvilinear patterns of various radii.

An important feature of this invention resides in the construction of the turntable T for enabling positive engagement with the work for guiding movement but which permits the work to be engaged and disengaged from the turntable in a simple and expedient manner for purposes of adjustment, removal or the like, As illustrated inl the gures, the turntable comprises a center post 20 which extends upwardly in alignment with the axis of the turntable and is provided with a point at the upper end 21 for easy insertion through the work at the point which is to form the center of the curvilinear pattern. Fixed as by weldinggto the lower end portion of the center post is a lower disc plate 22 lhaving its peripheral edge portion formed with a plurality of spaced triangular teeth 23 which are bent to extend angularly or curvilinearly in the upward direction. An upper disc plate 24 of substantially the same dimension as the lower plate 22 is similarly formed with teeth 25- in the periphery thereof but with the teeth extending angularly or curvilinearly downwardly with, the spaced relation between the ends of the teeth calibrated to permit the teeth of one disc member to extend into the distance between the teeth of the otherthereby positively to engage the work as by penetration. when the work is positioned therebetween. The upper disc plate is formed with a central opening 26 dimensioned to enable passage of the center post 20 for sliding. movement of the upper disc plate onto the post in the direction toward or away from the lower disc plate. Means are provided to establish resilient engagement between the upper disc plate and the post to prevent inadvertent displacement from position of use. Various means may be employed, such for example as the spring clips 27 and '28 secured to the upper surface of the disc plate 24 having a pair of spring arms extending angularly upwardly in opposite, directions to extend across the central opening 26 with openings 29 and 30 in the arms which are normally offset from alignment with the opening 26 in the plate so that the spring arms 27 and 28 willbe exed as the. openings are brought into registry with the. central opening 26 in the disc plate for passage of the center post 20 therethrough. As a result, the spring arms resiliently engage the post from opposite sides.

It will be apparent from the description that the disc plates and the center post will rotate as a unit about their axes. The center postis journalledfor rotational movement on theend of a slide plate 31 for shifting the axis ofthe turntable in the direction to increase or decrease the. spaced'relation with the sewing needle 12. For this purpose, theend portion of the slide plate is formed with an opening32 through which a portion 33 of the post depending` fromY the underside of the lower disc plate extends with disc members 34-V and 35 xed to the portion 33v of the post witha spaced relation therebetween correspondingto the thickness-of the slide plate and positioned on the opposite sides thereof to form a journal for the turntable.

The slide plate 31 constitutes an elongate member formed of rigid material having calibrations 36 along the length thereof for locating the journal in the desired spaced relation with the needle of the sewing machine. Another important feature of this invention resides in the means for mounting the slide plate and for holding the slide plate in fixed position while enabling adjustment thereof for varying the radius of curvature of the stitches that are formed in the work during normal operation of the machine.

For this purpose, the slide plate in the form of an elongate rule which rotatably mounts the turntable on one end thereof is received between laterally spaced guides 37 and 33 fixed to the upper surface of an adapter plate 39 with the vertically disposed side walls of the guide members spaced apart laterally by a distance corresponding to the width of the slide plate and having horizontally disposed ilanges extending inwardly from the upper edges of the side walls in spaced relation with the top wall of Ythe adapter plate corresponding to the thickness of the slide plate. As a result the slide plate is frictionally engaged at its lateral edges and at its upper and lower surfaces between the guide members and the adapter plate thereby to prevent upward displacement or lateral dispiacemnt while permitting longitudinal adjustment of the slide plate over the surface of the adapter.

While the laterally spaced guide members which embrace the top and side walls of the slide plate function, in part, to maintain the slide plate in the desired position of adjustment, it has been found expedient to employ separate means for engagement of the slide plate with suicient tension to militate against inadvertent movement from its position of adjustment. One such means illustrated in Figure l comprises a bracket 49 having a supporting arm which extends crosswise of a central portion of the slide plate and which is secured at its ends to the adapter plate, as by welding, soldering or the like. Extending longitudinally forwardly or rearwardly from an intermediate portion of the cross arm is a spring clip 41 having a curvilinear lip 42 on the end portion thereof which resiliently engages the upper surface of the slide plate 31 with suicient force to eliminate looseness and to prevent movement other than by manual adjustment to locate the slide plate in position of use. For manual operation of the slide plate, the plate is provided with a knob 43 which extends upwardly from the outer free end thereof.

Means are provided for removably securing the adapter plate which supports the slide plate to the bed plate of the machine. One such means may include a bracket in the form of a plate which depends integrally from the lower face of the adapter plate adjacent the forward end portion thereof. The plate is dimensioned to be insertable through the bobbin opening of the machine and to be received therein in fitting relation thereby to hold the adapter rigidly in position adjacent the upper surface of the bed plate of the machine. lt will be understood that other means may be employed for securing the adapter iii position of use but that the means described provides a method which is simple and easy to effect.

ln operation, the bracket for the adapter. plate is inserted rigidly to position the adapter in position of use. The work is then positioned on the turntable by inserting the needle through the work in the center of the circle to be stitched and then the top plate is threaded onto the needle and displaced downwardly rmly to engage lghe work between the top and bottom disc plates. 'lhe slide plate is then adjusted linearly to displace the axis of the turntable to the radius desired. As the machine is operated in the usual manner, the displacement of the work by the feed dog causes the work to swingabout the axis of the turntable to produce a curvilinear stitch therein.

To remove the work, the spring arms 27' and 28 are flexed inwardly by manual displacement to align the openings 29 and 30 for release of resilient engagement with the needle so that the top disc plate may be lifted olf of the needle to free the work.

L'Il

It will be apparent from the description that the needle, the journal members and the upper and lower discs of the turntable will all revolve together and that the clamping engagement of the work between the disc plates will cause the turntable to be rotated by the material during normal operation. Since the needle 12 penetrates the work when the latter is in position of use, displacement of the work from the axis of rotation is avoided with the result that a positive relation is established for guiding the work in a swinging movement to produce a perfect circle.

By adjustment of the slide plate to vary the spaced relation between the axis of the turntable and the sewing needle, the curvature of the pattern may be increased or decreased and by controlled movement linearly forwardly or back during operation it is also possible to sew spirals and other curvilinear designs in the work.

In the drawing, the element Sil represents additional guides rigid with the adapter plate for embracing the slide plate to guide the latter in linear movement, as distinguished from sidewise movement. The element 51 represents a guard rigid with the clamp plate and extending upwardly and over the end of the pin to protect the user against injury by engagement with the point of the pin in use when the clamp plate is displaced to or from clamping position.

It will be understood that the calibrations in the slide plate may, in the alternative, be provided in the adapter for registry with certain indications provided in the slide plate for prepositioning and it will be understood further that additional guides such as the guide members 50 may be employed for controlling movement of the side plate and that other changes may be made in the details of construction, arrangement and operation without departing from the spirit of the invention, especially as defined in the following claims.

We claim:

l. For use in combination with a sewing machine having a sewing needle for effecting sewing operations and a feed dog cooperating with the sewing needle for displacing the material linearly across the path of the sewing needle, an integrated, unitary attachment cooperating with the feed dog for converting linear movement to curvilinear movement of the material across the path of the sewing needle comprising a base plate, means integral with the base plate for removably mounting the base plate in fixed relation to one side of the feed dog, a slide plate mounted on the base plate for shifting movement over the base plate between extended and retracted positions of adjustment, a turntable mounted on the end portion of the slide plate for free rotational movement on the slide plate, a shaft having a pointed end rigid with and extending upwardly axially from the turntable, a clamp plate displaceable endwise over the shaft in the direction toward and away from the turntable between clamping position and displaced positions of adjustment, and means on the clamping plate operative resiliently to engage the shaft for holding the clamp plate in clamping position of adjustment.

2. An attachment as claimed in claim l which includes guide means on the base plate operatively engaging the slide plate to guide the latter during movement between extended and retracted positions.

3. An attachment as claimed in claim l which includes means on the base plate resiliently engaging the slide plate for holding the slide plate in the desired position of adjustinent.

4. An attachment as claimed in claim l which includes calibrations on one of the elements consisting of the base and slide plate for indicating the position of adjustment of the slide plate.

5. An attachment as claimed in claim l which includes a guard arm rigid with the clamp plate and extending upwardly therefrom over the point of the shaft when the i clamp plate is in clamping position.

6. An attachment as claimed in claim 1 in which the turntable and clamp plate comprise circular disc plates having the peripheral edge portions turned inwardly in the direction towards each other for clamping engagement of the material to be sewed therebetween.

7. An attachment as claimed in claim 6 in which the inturned end portions of the turntable and clamp plate are formed with notches throughout the periphery thereof.

8. For use in combination with a sewing machine having a sewing needle for effecting sewing operations and a feed dog cooperating with the sewing needle for displacing the material linearly across the path of the sewing needle, an integrated, unitary attachment cooperating with the feed dog for converting linear movement to curvilinear movement of the material across the path of the sewing needle comprising a base plate, means integral with the base plate for removably mounting same in xed relation to one side of the feed dog, a slide plate mounted on the base plate for shifting movement over the base plate in a direction toward and away from the sewing needle, a turntable mounted on the end portion or" the slide plate for free rotational movement on an end portion of the slide plate, a pin rigid with the turntable and extending upwardly axially therefrom, a clamp plate dimensioned to correspond to the turntable having an opening in the central portion thereof to enable shifting movement axially over the pin between clamping and disengaged positions of adjustment, means on the clamp plate for resiliently engaging said pin when in clamping position, and a guard rigid with said clamp plate extending over the end of the pin when in clamping position.

References Cited in the le of this patent UNITED STATES PATENTS 117,867 Coles Aug. 8, 1871 

